1. Technical Field
The present invention relates to a method for detecting a biomaterial. Particularly, the present invention relates to a method for detecting a biomaterial, which can detect antigen in rapid and convenient way, from the color transition of a nano-probe made of polydiacetylene (PDA) of which color can be changed by applying stimuli.
2. Description of the Related Art
Most types of polydiacetylene biosensors use a synthetic receptor, while sensors wherein antibodies are selectively immobilized have been hardly found so far. In 2003, an immunodetective method using polydiacetylene was developed and disclosed in a US research. However, its fabrication method is so complicated that a novel immunodetective alternative has still been in need.
Currently, many researches related to polydiacetylene are being made in various parts of the world, but most of those researches are only in the level of experiments on the physical and chemical properties of polydiacetylene molecules, providing theoretical grounds for its potential use as a biosensor. The present inventors believe that the domestic studies on polydiacetylene sensors have already reached to world-class level, and further to the leading position particularly in the technical field of chip fabrication using polydiacetylene.
As for quantitative measures using antibodies, Enzyme Immunoassay (EI), Enzyme-Linked Immunosorbent Assay (ELISA) and Radioimmunoassay (RIA) may be generally mentioned.
The ELISA method which uses an antigen-antibody reaction with an antibody bound with an enzyme is being increasingly used, owing to its advantages such as great sensitivity as much as that of RIA, while using no radioactive ray. However, it also has disadvantages such that it requires a great amount of samples for the assay, a long reaction time and various steps to be taken. As for RIA which shows the highest sensitivity among other methods, it has a risk of using radioactive materials.
For solving the problems of prior arts, other analytical methods which use isotope, fluorescence and enzyme reaction and are capable of exhibiting signal transformation, have been suggested. Among such alternatives, a method using isotope measurement has a safety problem; a method using an enzyme reaction shows a narrow analytical range, thereby not being suitable for samples at various concentrations; and a method using fluorescence measurement needs a step of binding a costly fluorescent material to protein to be detected for use.
In order to dissolve such problems, label-free detection methods such as those using polydiacetylene have been suggested. Polydiacetylene refers to a polymer of diacetylene monomers, having alternate triple bonds. Diacetylene is known to form a supramolecule like a liposome, Langmuir-Blodgett (LB) or Langmuir-Schaeffer (LS) monolayer, owing to its amphoteric property. When diacetylene supramolecule is exposed to UV light, polymerization occurs between adjacent diacetylenes, developing a blue color. The polymerized polydiacetylene supramolecule has a unique property of specific blue-to-red color transition by various stimuli such as temperature, pH change, friction, surfactant, solvent or the like. The color transition of polydiacetylene is determined by the length of n-conjugation in the polymer and the resulting conformation of the molecules. Owing to the characteristics, it is possible to fabricate various types of sensors by varying the conjugation in polydiacetylene polymers. However, such polydiacetylene biosensors in prior arts produce a weak signal on materials to be detected due to instable polydiacetylene immobilization.
In order to solve the technical problems of prior arts, the present invention provides a method for detecting biomaterials which can effectively detect a biomaterial at low concentration by reinforcing the interlinks between polydiacetylene liposomes owing to the use of an interlinker such as diamine, thereby making the polydiacetylene liposomes layered in a sensor chip and thus amplifying the fluorescent signal.
The present inventors have made a great effort to solve the technical problems of conventional arts, and developed a method comprising fabricating a chip by rigidly binding polydiacetylene liposomes and immobilizing the layers thereof onto a substrate, reacting the resulted chip with a biomaterial and confirming an amplified calorimetric signal owing to color transition upon said reaction, thereby completing the present invention.